Overhead conveyors are utilized in various production, transportation, assembly and treatment environments to transport parts or products through various operational stages. One type of overhead conveyor employs a rotating, generally horizontal drive tube or shaft that supports trolleys from which the load is suspended. Drive wheels on the trolleys ride on the upper surface of the rotating drive tube, and each is mounted for rotation about a driven wheel axis that is non-parallel and non-perpendicular to the drive tube axis, preferably at an acute angle to the drive axis. To support the load, the trolleys are also provided with wheels that ride on rails that define the load track. In layouts where the trolleys repeatedly traverse side-by-side, supply and return sides of the conveyor (or a loop), a powered curve cannot be used unless the supply and return sides of the line are spaced apart a sufficient distance to accommodate two 90-degree turns to form a 180-degree turn at each end of the line. This typically consumes six or seven feet of floor space at each 180-degree turn, resulting in excessive dead space between the lines and restricting the design of an efficient conveyor layout.